Field of the Invention
The present invention relates to a mineral compound for reducing the concentration of inorganic phosphates in bodily fluids and dialysis fluids.
The present invention relates to a mineral compound for reducing the concentration of inorganic phosphates in bodily fluids and dialysis fluids according to claim 1.
Description of Related Art
Phosphates play an important role in human metabolism and are vital for the function of the human organism. Phosphates usually are supplied by the food and reabsorbed in the intestines. Up to 70% of the phosphates ingested with the food are excreted via the kidneys and the urine. The rest is utilized by the organism. In humans with healthy kidneys the amount of phosphate excreted in the urine per day is about 900 mg on average.
When the normal phosphate values in blood are exceeded, however, the low solubility product of calcium phosphate will lead to its deposition in the vascular systems and a related calcification.
In the case of an insufficient excretion capacity of the kidneys such as in the case of the renal insufficiency, phosphate will be concentrated in the organism of the patients in an undesired quantity, so that an elevated phosphate level occurs in the blood (hyperphosphatemia).
Chronic renal insufficiency is characterized by a slow progressive loss of the renal function. Main causes are inflammations and infections of the kidneys, constriction of the efferent urinary tract and congenital renal diseases. In industrial nations, however, there is an increase in type 2 diabetes mellitus and arterial hypertension-induced renal insufficiency. Renal insufficiency can only can be treated by a renal replacement therapy in the form of a lifelong therapy with dialysis or kidney transplantation.
For renal insufficiency patients, the instrumental extracorporeal hemodialysis is a life-sustaining therapy, which in part over many years must take over the excretory function of the kidneys. In Germany, about 78,000 patients are treated with a renal replacement therapy. More than 5 million people worldwide are suffering from the chronic kidney disease. Despite a constant development and improvement of the dialysis technique, dialysis patients exhibit a morbidity and mortality rate significantly above the level of the normal population. The reason are secondary complications in several organ systems due to a progressing accumulation of uremia toxins which are responsible for the increased cardiovascular risk.
Currently, 115 uremia toxins are known, one of which is phosphate. The phosphate from the group including the small-molecular water-soluble uremia toxins is subject to a permanent control, since the chronic renal insufficiency leads to a hyperphospatemia and is a decisive risk factor for mortality. A reduction of the phosphate supply should be achieved by dialysis, a low-phosphate diet and an intake of phosphate-binding drugs. The reduction of the phosphate concentration in the plasma during the dialysis only is insufficient, however, so that a further reduction of the exogenous phosphate supply is necessary.
By means of phosphate elimination by phosphate-binding drugs, the phosphate quantities ingested with the food should be bound in the gastrointestinal tract and prevented from passing over into the blood stream. Established therapeutic agents are aluminum and calcium salts. However, they are characterized by considerable side effects. Deposits of aluminum in the skeletal system and brain lead to severe impairments of the hematopoiesis and of cerebral functions. Due to the development of a hypercalcemia and the rise in calcium phosphate, calcium salts are highly disadvantageous. Sevelamer and lanthanum carbonate (Fosrenol) are recently developed calcium-free and aluminum-free phosphate binders. The most frequent side effects of all four phosphate binders include disorders of the gastrointestinal tract. Fosrenol, for example, like the other clinically used phosphate binders, can cause gastrointestinal disorders such as nausea, vomiting, diarrhea, constipation, abdominal pain, headache, seizures and encephalopathy. Lanthanum also has a long half-life and is concentrated in bones and various tissues, such as teeth, liver, kidneys or brain.
In addition, drug therapy is permanent and thus represents a considerable cost burden for the health system.
Therefore, it is the problem underlying the present invention to provide a compound or composition for reducing the exogenous phosphate supply or for reducing the phosphate content in the plasma, which does not have the above-mentioned disadvantages.